Conductor rail fish-plate

ABSTRACT

The invention relates to a conductor rail fish-plate for the electrical and mechanical connection of successive conductor rails. Said fish-plate has two symmetrical half-profiles ( 4 ), which encompass the exterior profile of the conductor rail ( 1 ). The two half-profiles ( 4 ) are braced against one another using screws. Contact strips ( 18 ) are arranged in the contact zone between the conductor rail ( 1 ) and the respective half-profiles ( 4 ), said strips coming into contact with the respective surfaces by means of a large number of spring-loaded contacts.

[0001] The invention concerns a conductor rail fish plate according tothe preamble of claim 1.

[0002] Increasing demands on overhead contact line systems in terms ofsafety, reliability, current carrying capacity, short-circuitresistance, and minimal installation height have led to the use ofconductor rails holding a contact wire not carrying a tensile load.Preferred fields of application are tunnels, and also maintenanceworkshops for electric motor vehicles, so that the work-hinderingcontact lines can be swung to the side.

[0003] Conductor rail profiles are usually molded in lengths of ca. 12meters. Conductor rail systems are assembled from successive conductorrail profiles, which must be connected mechanically and electrically. Onone hand, the connection requires mechanical strength, maintenance ofpositive fit, and also transmission capacity for electrical current,which can reach up to 5000 A in current spikes. The positive fit demandsthat under the load of its own weight, no bends may appear at the jointof two successive conductor rail profiles.

[0004] Deformation-free joints of two conductor rail profiles werepreviously achieved with two plates at the inside of the crosspieces ofthe conductor rail profiles. These fish plates must be inserted into thehollow spaces of the conductor rails. Then they are pushed against theprofile crosspieces from the outside with screws. The mechanical andpositive-fit strength is achieved through wedge-shaped edges on the fishplates and counter shapes in the profile interiors. The electricaltransmission of current is realized through linear contact between thefish plates and the crosspieces inside of the profile. The linearcontacts are achieved through pressure from the tightening of thescrews.

[0005] A disadvantage for this known conductor rail joint is that twoplates must be inserted, holes must be bored in the crosspiece profilesand the plates, and the corresponding number of screws must betightened. In practice, 16 holes or even threaded holes are bored ineach plate and the threads cut. The known conductor rail joint is thusnot assembly-friendly. It is also not practical when a conductor railsection must be exchanged, because access to the hollow space on theconductor rail profile is possible only with a narrow object at thelower clamp opening for the contact wire. The linear, not clearlydefined electrical contacts set limits on the current transmission.

[0006] The task of the invention is to improve the known conductor railjoint such that it is easy to assemble, it has a defined currenttransmission for high electrical currents, and it features highmechanical strength at least equal to that of the known conductor railprofile and it can be detached on demand. This task is accomplished bythe features listed in claim 1. Advantageous configurations andrefinements of the invention can be taken from the subordinate claims.

[0007] The basic principle of the invention is that the conductor railfish plate consists of two symmetrical half profiles, which overlap theexterior of the conductor rail profile and which are attached to theconductor rail profile by a screw connection on the outside of thecross-sectional profile of the conductor rail, and additionalspring-loaded contact strips are arranged between the plates and theconductor rail profile.

[0008] Therefore, no holes are necessary in the conductor rail profile.Because the half profiles are attached to the conductor rail profile onthe outside and overlap this profile, very easy assembly can berealized. The mechanical strength is achieved by the pre-tensioning ofthe two half profiles with screws. Through the contact strips, thepre-tensioning of the conductor rail fish plates realizes defined pointcontacts between the fish plate and the conductor rail profile. Theprofile crosspieces of the conductor rail profile are not impaired intheir elasticity, so that a contact wire pull-in car can also straddlethe profile unimpaired. The conductor rail joint can be detached easilyfrom outside. Also, repeated loosening and tightening is possiblewithout additional means.

[0009] In the following, the invention is explained in connection withthe drawing with reference to an embodiment. Shown are:

[0010]FIG. 1, a cross section of a conductor rail with a conductor railfish plate according to the invention;

[0011]FIG. 2, a side view of the conductor rail joint and plate of FIG.1, FIGS. 3 and 4, top views and cross sections of contact strips, whichare used with the invention;

[0012]FIG. 5, a side view of a conductor rail fish plate; and

[0013]FIG. 6, a section along the line VI-VI of FIG. 5.

[0014] In FIG. 1, a known conductor rail profile 1 can be seen, whichholds a contact wire 2. Such a conductor rail profile is known, e.g.,from EP 0 828 629 A1. At a joint (3 in FIG. 2) of two adjacent conductorrails, two symmetrical conductor rail fish plates (in the followingcalled “plates”) 4 are attached, which are extrusion molded or milled.These plates 4 overlap the exterior of the conductor rail profile andeach have a groove 5, in which a top, horizontal crosspiece 6 of theconductor rail profile projects. Each plate 4 has a head 7 with a hole8, a center part 9, and a bottom crosspiece 10, which connects to thecenter part 9. The mentioned groove 5 is located between the head andcenter part. The head 7 overlaps the conductor rail profile 4 almost upto its center 11, while the inside 12 of the center part 9 and thecrosspiece 10 pointing towards the conductor rail profile 4 are shiftedoutwards and feature a spacing 13 relative to the conductor railprofile, so that it is possible to widen or bend the conductor railprofile 1 in order to insert the contact wire 2. The crosspiece 10 isthus shaped like a plate and is used to guarantee the mechanicalflexural strength in the longitudinal direction of the conductor rail 1.

[0015] The transition region between the groove 5 and the inside 12 isprovided with a rounded section 14, which comes into contact with adiagonal section 15 of the conductor rail in the transition regionbetween the horizontal crosspiece 6 and the vertical crosspiece 16 ofthe conductor rail when the plates are assembled. This provides a linearcontact in the contact region. If the two symmetrical half profiles 4are tensioned against each other by a screw through the hole 8, then thetwo half profiles 4 are not only pushed against each other, but are alsopressed with the top, downwards pointing surface 17 of the head 7against the top side of the conductor rail profile 1 due to the roundedsection 14 in connection with the diagonal section 15. In the surface17, the two half profiles each have a recess, in each of which a set ofspring-loaded contact strips 18 is inserted. Through the verticaltightening of the half profiles, the contact strips are pressed withdefined force against the conductor rail 1 and the half profiles 4 overthe entire length of the half profiles, so that a very good multiplecontact is produced, which bridges the joint 3.

[0016] In the shown embodiment, the horizontal extent of the groove 5 inthe cross section of FIG. 1 is longer than that of crosspiece 6, so thatthe free ends of the crosspieces do not come into contact with the baseof the groove 6. This has the effect that the rounded section 14 incontact with the diagonal section 15 always comes into use.

[0017] The section of the center part 9 directed downwards towards thecontact wire 2 is provided with a bevel 19. Furthermore, a bevel 20 isformed in the transition region between the center part 9 and thecrosspiece 10. Incidentally, all other edges are provided with a roundedsection.

[0018] The length of the plates in the travel direction depends on thedesired mechanical and electrical properties and in practice equalsbetween 200 and 400 mm according to current transmission capacity.According to the length and mechanical strength, two to four screws areused. There is a corresponding number of holes 8 in the head part. Foranother embodiment, four screws are always used, independent of thelength of the plates.

[0019] In the side view of FIG. 2, above all the joint 3 between twoadjacent conductor rail profiles can be seen, as well as several holes8. The selected center separating line indicates that the length of thehalf profiles can be varied in the travel direction.

[0020]FIGS. 3 and 4 show two variants of contact strips. FIG. 2a shows atop view and FIG. 2b a schematic cross section. Overall, the contactstrips have two parallel connecting pieces 20 and 21, between whichthere is a plurality of spring contacts 22, which are connected to thetwo crosspieces 20 and 21. The contacts 22 curve outwards alternatelyfrom a center plane 23. In addition, the two crosspieces 20 and 21 canbe bent outwards from this plane 23. If the profile elements 4 of FIGS.1 and 2 are pressed against the conductor rail, then primarily thecontacts 22 and in the case of the bent crosspieces 20 and 21 also thecrosspieces come into contact with the conductor rail 1 and the profilerail 4 and thus form an electrical connection.

[0021]FIG. 4 shows another variant, for which the contacts 22 bulge outonly to one side like an arc. Obviously, other shapes of contact stripsare also possible. However, the essential advantage is that a pluralityof contact points is always available and the individual contacts arepressed with defined spring force against the corresponding surfaces, sothe desired good electrical connection is produced.

[0022] In addition to the holes 8, the plates 4 can also have threadedholes 24 or 25, which simplify disassembly. The threaded holes 24 or 25thus go through only one plate of a pair of opposing plates, so thatwhen screwing in one screw into one of the threaded holes 24 or 25, itsfront end then supports at the opposing plate and thus the two plates 4and 4′ are pressed apart. The threaded holes 24 and 25 can bemirror-inverted to a center line 26. Obviously, it would also bepossible to form the threaded holes only on one side, i.e., in oneplate. The formation in the two opposing plates has the advantage ofbetter accessibility of at least one of the threaded holes in theinstalled state.

1. Conductor rail fish plate characterized by two mirror-inverted plates (4), which overlap the exterior of a conductor rail (1) in the region of a joint (3) between adjacent conductor rails (1), wherein the plates (4) can be tensioned against each other with a screw connection (8) on the outside of the cross-sectional profile of the conductor rails (1), and electrical contact strips (18) with a plurality of spring-loaded contacts (22) are arranged between the plates (4) and the conductor rails (1) to be connected.
 2. Conductor rail fish plate according to claim 1, characterized in that the plates have a groove (6), in which one leg (7) of the conductor rail profile (1) engages, and the contact strips (18) are arranged in this groove.
 3. Conductor rail fish plate according to claim 1 or 2, characterized in that the plate (4) has a head (2) [sic; (7)] with a hole (3) [sic; (8)], a center part (4) [sic; (9)], and a crosspiece (5) [sic; (10)] connecting to this center part with a thin cross section relative to the center part, and the center part (4) and the crosspiece (5) have a spacing (13) relative to the conductor rail profile (1).
 4. Conductor rail fish plate according to claim 3, characterized in that in the transition between the groove (5) and the center part (4) there is a rounded section (14), which can be brought into contact with a diagonal section (15) of the conductor rail profile (1) and thus tensions the contact strips (18) between the top side (17) of the head (7) when tightening the screw connection (8).
 5. Conductor rail fish plate according to one of claims 1-4, characterized in that the contact strips (18) overlap the joint (3) in the longitudinal direction of the conductor rail and essentially extend over the entire length of the plate (4).
 6. Conductor rail fish plate according to claim 5, characterized in that in the bottom side (17) of the head (7) there is a recess, in which the contact strips are inserted.
 7. Conductor rail fish plate according to one of claims 1-6, characterized in that the plates are extrusion molded or milled.
 8. Conductor rail fish plate according to one of claims 1-7, characterized in that at least one plate of a corresponding pair of mirror-inverted plates has a threaded hole (24, 25), which completely penetrates the head (7) of the plate. 